From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: x86@kernel.org, linux-sgx@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Jethro Beekman <jethro@fortanix.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
akpm@linux-foundation.org, andriy.shevchenko@linux.intel.com,
asapek@google.com, bp@alien8.de, cedric.xing@intel.com,
chenalexchen@google.com, conradparker@google.com,
cyhanish@google.com, dave.hansen@intel.com,
haitao.huang@intel.com, josh@joshtriplett.org,
kai.huang@intel.com, kai.svahn@intel.com, kmoy@google.com,
ludloff@google.com, luto@kernel.org, nhorman@redhat.com,
npmccallum@redhat.com, puiterwijk@redhat.com,
rientjes@google.com, tglx@linutronix.de, yaozhangx@google.com
Subject: [PATCH v34 09/24] x86/sgx: Add __sgx_alloc_epc_page() and sgx_free_epc_page()
Date: Tue, 7 Jul 2020 06:01:49 +0300 [thread overview]
Message-ID: <20200707030204.126021-10-jarkko.sakkinen@linux.intel.com> (raw)
In-Reply-To: <20200707030204.126021-1-jarkko.sakkinen@linux.intel.com>
Add __sgx_alloc_epc_page(), which iterates through EPC sections and borrows
a page structure that is not used by anyone else. When a page is no longer
needed it must be released with sgx_free_epc_page(). This function
implicitly calls ENCLS[EREMOVE], which will return the page to the
uninitialized state (i.e. not required from caller part).
Acked-by: Jethro Beekman <jethro@fortanix.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
arch/x86/kernel/cpu/sgx/main.c | 62 ++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/sgx/sgx.h | 3 ++
2 files changed, 65 insertions(+)
diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index c5831e3db14a..97c6895fb6c9 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -83,6 +83,68 @@ static bool __init sgx_page_reclaimer_init(void)
return true;
}
+static struct sgx_epc_page *__sgx_alloc_epc_page_from_section(struct sgx_epc_section *section)
+{
+ struct sgx_epc_page *page;
+
+ if (list_empty(§ion->page_list))
+ return NULL;
+
+ page = list_first_entry(§ion->page_list, struct sgx_epc_page, list);
+ list_del_init(&page->list);
+
+ return page;
+}
+
+/**
+ * __sgx_alloc_epc_page() - Allocate an EPC page
+ *
+ * Iterate through EPC sections and borrow a free EPC page to the caller. When a
+ * page is no longer needed it must be released with sgx_free_epc_page().
+ *
+ * Return:
+ * an EPC page,
+ * -errno on error
+ */
+struct sgx_epc_page *__sgx_alloc_epc_page(void)
+{
+ struct sgx_epc_section *section;
+ struct sgx_epc_page *page;
+ int i;
+
+ for (i = 0; i < sgx_nr_epc_sections; i++) {
+ section = &sgx_epc_sections[i];
+ spin_lock(§ion->lock);
+ page = __sgx_alloc_epc_page_from_section(section);
+ spin_unlock(§ion->lock);
+
+ if (page)
+ return page;
+ }
+
+ return ERR_PTR(-ENOMEM);
+}
+
+/**
+ * sgx_free_epc_page() - Free an EPC page
+ * @page: an EPC page
+ *
+ * Call EREMOVE for an EPC page and insert it back to the list of free pages.
+ */
+void sgx_free_epc_page(struct sgx_epc_page *page)
+{
+ struct sgx_epc_section *section = sgx_get_epc_section(page);
+ int ret;
+
+ ret = __eremove(sgx_get_epc_addr(page));
+ if (WARN_ONCE(ret, "EREMOVE returned %d (0x%x)", ret, ret))
+ return;
+
+ spin_lock(§ion->lock);
+ list_add_tail(&page->list, §ion->page_list);
+ spin_unlock(§ion->lock);
+}
+
static void __init sgx_free_epc_section(struct sgx_epc_section *section)
{
struct sgx_epc_page *page;
diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h
index dff4f5f16d09..fce756c3434b 100644
--- a/arch/x86/kernel/cpu/sgx/sgx.h
+++ b/arch/x86/kernel/cpu/sgx/sgx.h
@@ -49,4 +49,7 @@ static inline void *sgx_get_epc_addr(struct sgx_epc_page *page)
return section->va + (page->desc & PAGE_MASK) - section->pa;
}
+struct sgx_epc_page *__sgx_alloc_epc_page(void);
+void sgx_free_epc_page(struct sgx_epc_page *page);
+
#endif /* _X86_SGX_H */
--
2.25.1
next prev parent reply other threads:[~2020-07-07 3:04 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 3:01 [PATCH v34 00/24] Intel SGX foundations Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 01/24] x86/cpufeatures: x86/msr: Add Intel SGX hardware bits Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 02/24] x86/cpufeatures: x86/msr: Add Intel SGX Launch Control " Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 03/24] x86/mm: x86/sgx: Signal SIGSEGV with PF_SGX Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 04/24] x86/sgx: Add SGX microarchitectural data structures Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 05/24] x86/sgx: Add wrappers for ENCLS leaf functions Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 06/24] x86/cpu/intel: Detect SGX support Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 07/24] x86/cpu/intel: Add nosgx kernel parameter Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 08/24] x86/sgx: Initialize metadata for Enclave Page Cache (EPC) sections Jarkko Sakkinen
2020-07-07 3:01 ` Jarkko Sakkinen [this message]
2020-07-07 3:01 ` [PATCH v34 10/24] mm: Add vm_ops->mprotect() Jarkko Sakkinen
2020-07-07 3:14 ` Matthew Wilcox
2020-07-07 3:22 ` Sean Christopherson
2020-07-07 3:24 ` Matthew Wilcox
2020-07-07 4:01 ` Jarkko Sakkinen
2020-07-07 4:10 ` Matthew Wilcox
2020-07-08 14:33 ` Jarkko Sakkinen
2020-07-08 14:37 ` Matthew Wilcox
2020-07-08 16:10 ` Jarkko Sakkinen
2020-07-08 22:56 ` Jarkko Sakkinen
2020-07-07 4:03 ` Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 11/24] x86/sgx: Add SGX enclave driver Jarkko Sakkinen
2020-07-07 3:36 ` Matthew Wilcox
2020-07-07 4:11 ` Jarkko Sakkinen
2020-07-07 4:29 ` Sean Christopherson
2020-07-07 4:39 ` Matthew Wilcox
2020-07-07 4:46 ` Sean Christopherson
2020-07-07 3:01 ` [PATCH v34 12/24] x86/sgx: Add SGX_IOC_ENCLAVE_CREATE Jarkko Sakkinen
2020-07-07 3:29 ` Sean Christopherson
2020-07-07 4:04 ` Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 13/24] x86/sgx: Add SGX_IOC_ENCLAVE_ADD_PAGES Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 14/24] x86/sgx: Add SGX_IOC_ENCLAVE_INIT Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 15/24] x86/sgx: Allow a limited use of ATTRIBUTE.PROVISIONKEY for attestation Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 16/24] x86/sgx: Add a page reclaimer Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 17/24] x86/sgx: ptrace() support for the SGX driver Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 18/24] x86/vdso: Add support for exception fixup in vDSO functions Jarkko Sakkinen
2020-07-07 3:01 ` [PATCH v34 19/24] x86/fault: Add helper function to sanitize error code Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 20/24] x86/traps: Attempt to fixup exceptions in vDSO before signaling Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 21/24] x86/vdso: Implement a vDSO for Intel SGX enclave call Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 22/24] selftests/x86: Add a selftest for SGX Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 23/24] docs: x86/sgx: Document SGX micro architecture and kernel internals Jarkko Sakkinen
2020-07-07 3:02 ` [PATCH v34 24/24] x86/sgx: Update MAINTAINERS Jarkko Sakkinen
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